Due to their good stability, chelate complexes of the pyrrole ring systems such as porphyrins have been quite thoroughly studied and characterized. The coordination of a pyrrolecarbaldimine with an alkyl group as a substituent of the imine function has been studied with Cobalt, Nickel, Palladium, Copper (Inorg. Chem. 1964, 3, 1521; Inorg. Chem. 1966, 5, 625; Inorg. Chem. 1977, 16, 1341).
Numerous and important applications have been found for pyrrolecarbaldimine complexes such as post-metallocene catalysis of ethylene polymerization with titanium (Organometallics, 2001, 20, 4793) and hafnium (J. Chem. Soc. Dalton Trans. 2002, 4529) complexes, and facile C—H activation with platinum derivatives (J. Am. Chem. Soc. 2003, 125, 12674).
Heteroleptic complexes including at least one pyrrolecarbaldimine ligand are scarcely reported in the literature. Journal of the Indian Chemical Society (1984), 61(7), 571-2 describes a method of synthesizing heteroleptic nickel, copper, palladium and platinum pyrrolylcarbaldimine/acetylacetonate compounds. Chemical Communications (2009), (12), 1550-1552 describes a method for synthesizing heteroleptic palladium pyrrolylcarbaldimine/fluorinated acetylacetonate. Polyhedron (1995), 14(15/16), 2179-87 describes a method of synthesizing nickel pyrrolylcarbaldimine/ketoiminato where the pyrrolylcarbaldimine and the ketoiminato are bridged.